1. Field of the Invention
The present invention relates to systems and methods for protecting vehicle occupants from injury. More specifically, the present invention relates to inflators and associated electrical connectors for airbag systems.
2. Description of Related Art
The inclusion of inflatable safety restraint devices, or airbags, is now a legal requirement for many new vehicles. Airbags are typically installed in the steering wheel and in the dashboard on the passenger side of a car. In the event of an accident, an accelerometer within the vehicle measures the abnormal deceleration and triggers the expulsion of rapidly expanding gases from an inflator. The expanding gases fill the airbags, which immediately inflate in front of the driver and passenger to protect them from impact against the windshield.
Side impact airbags such as inflatable curtains and seat mounted airbags have also been developed in response to the need for protection from impacts in a lateral direction, or against the side of the vehicle. Other airbags such as knee bolsters and overhead airbags also operate to protect various parts of the body from collision.
A variety of inflator types are typically used to inflate such airbags. Known inflators generally fall into three categories: pyrotechnic inflators, compressed gas inflators, and hybrid inflators. Pyrotechnic inflators depend solely on combustion to provide inflation gas, while compressed gas inflators may use only a minimal amount of pyrotechnic that opens a chamber to release the inflation gas from a compressed state. Hybrid inflators use a combination of combustion and compressed gas storage to provide the inflation gas to fill the cushion.
Many known inflators contain an initiator, also known as a “squib,” that ignites in response to receipt of an electrical activation signal. The squib may be sealed and/or mounted in the inflator through the use of techniques such as insert molding. Unfortunately, such techniques can be quite time consuming and labor intensive. Insert molding often requires manual positioning of a part within a mold. Thus, fully automated production is not feasible.
Many inflators require the presence of a hermetic seal to keep moisture from entering the interior of the inflator to interfere with pyrotechnic materials or to prevent compressed gases from leaking out of the inflator. O-rings and other sealing mechanisms may be disposed around the initiator to provide sealing. However, such sealing devices add expense to the inflator. Furthermore, such additional sealing parts may accidentally be omitted during assembly.
As mentioned above, an activation signal is used to trigger ignition of the initiator. The activation signal is provided by an electronic control unit, or ECU, that reacts to a collision involving the vehicle by transmitting the activation signal. The ECU is connected to the inflator by an electric line that terminates in a connector electrically coupled to the initiator.
Unfortunately, many known connectors must be oriented prior to assembly. Dual-pin connectors, for example, must be aligned in a specific orientation, or at best, one of two opposite orientations. Single-pin connectors provide the ability to install the connector at any orientation. However, such connectors typically include no feature to prevent rotation of the connector after assembly. Hence, the connector may rotate within the inflator under the vibrations induced by vehicle operation. This rotation may produce undesirable noise or abrade away the conductive surfaces within the connector or the inflator, thereby endangering the integrity of the electrical connection.
Furthermore, many known inflators have comparatively expensive interlock mechanisms designed to receive the associated connector. For example, many inflators have an insert with an undercut, interior groove that interlocks with the connector. Such interior features must often be produced through methods such as machining, and are therefore time and labor intensive to produce. Such costs add significantly to the overall cost of the inflator.